Strong permanent magnet with tungsten, molybdenum, or chromium



Patented Jan. 14, 1936 UNITED STATES PATENT OFFICE;

STRONG PERMANENT MAGNET WITH TfJNG- STEN, MOLYBDENULI, R CHROMIUM Tolrnshichi Mishima, Ochiai-machi, Toyotama-gori, Tokyo, Japan No Drawing. Original application January 20,

1932, Serial No. 587,822. Divided and this application May 31, 1933, Serial No. 673,795. In

Japan March 9, 1931 8 Claims.

mainder substantially iron, with or without the and also small impurities. The subject matter of the invention is a division from the above mentioned application.

According to the invention it has been found that by adding tungsten to the new alloy as mentioned above, the alloy can further be improved in its characteristic properties, giving a higher coercive force and a. stronger residual magnetism, as well as a better malleability and ductility. In consequence the alloy is also suitable for making magnets required to be finished by complicated and precise working. The amount of tungsten to be added is 0.5 to 8%. The tungsten makes the grain-size minute and serves to increase the number 0112118 molecular magnets arranged irregularly at the boundary of the grains. It is due to this fact that a high coercive force and good residualmagnetism as well asgood toughness can be obtained...

Actual examples for carrying out the invention thus modified are given below:

Chemical composition (per cent) Magnetic properties Coercive Residual Iron Nickel 333 Tungsten force (He) magnetism aus (sa netism. Besides the forging property of the alloy is much improved.

Actual examples for this case are given below:

Chemical composition (per cent) Magnetic properties 5 Coercive Residual Iron Nickel gg 333 force (He) magnetism (sen 10 65.0 24. 5 l0. 0 0. 5 290 0, e00 62.0 23. 0 l0. 0 5. 0 300 9,400 56.0 30. 0 12. 0 2. 0 490 9, 500

In this case also it is noted that the presence of carbon of below 1.5% and/or a small amount of impurities does not materially affect the o z:

netic properties of the alloy.

According to the invention it has further been found that by adding 1 to 5% chromium and/or below:

Chemical composition (per cent) Magnetic properties Alumim Coercive Residual Iron Nickel mm Chrome Carbon force (He) magnetism auss) r) (saw Rest 18.0 10.0 3.0 0.1 172 10,000 62.5 24. 8 10. 0 2. 3 0. 2 265 9, 700 54.3 30.5 12.0 3.0 0.2 500 9,600

What I claim is:

l. A permanent magnet comprising main and auxiliary elements, the main elements consisting of nickel 5 to aluminum 7 to 20% and the remainder iron; the auxiliary elements consisting of one of the metals chromium from 1.0 to 5%, tungsten from 0.5 to 8% and molybdenum from trace to 10%.

auxiliary elements, the main elements consisting of nickel 5 to 40%, aluminum '7 to 20% and the remainder substantially iron; the auxiliary elefor this case are illustrated 25 4'5 2. A permanent magnet comprising main and merits consisting of one of the metals chromium so 6. A permanent magnet comprising nickel 5 to 40%, aluminum 7 to 20%, molybdenum from trace to 10%, carbon from trace to 1.5% and the remainder iron.

7. A permanent magnet comprising nickel 5 to 40%, aluminum '7 to 20%, chromium 1 to 5% ancl'the remainder iron.

8. A permanent magnet comprising nickel 5 to 40%, aluminum 7 to 20%, chromium 1 to 5%,

carbon from trace to 1.0% and the remainder 10 iron.

TOKUSHICHI MISHIMA. 

